docs: def is_build_dir(self, folder_name):
          """Return whether or not the given dir contains a build."""
          # Cannot move up to base scraper due to parser.entries call in
          # get_build_info_for_date (see below)
  
          url = '%s/' % urljoin(self.base_url, self.monthly_build_list_regex, folder_name)
          if self.application in APPLICATIONS_MULTI_LOCALE \
                  and self.locale != 'multi':
              url = '%s/' % urljoin(url, self.locale)
  
          parser = self._create_directory_parser(url)
  
          pattern = re.compile(self.binary_regex, re.IGNORECASE)
          for entry in parser.entries:
              try:
                  pattern.match(entry).group()
                  return True
              except Exception:
                  # No match, continue with next entry
                  continue
          return False